1. Field of the Invention
The present invention relates to ankle foot orthopaedic devices.
2. The Prior Art
The dominant motion of the foot relative to the lower leg as required for walking and running occur through what is commonly described as the ankle joint. The ankle joint comprises two major joints each with a dominant axis of motion. The joint formed between the lower surface of the tibia and upper surface of the talus is known as the tibio-talar joint. The tibio-talar joint enables the foot to be raised and lowered or dorsiflexed and plantaflexed using medical terminology. The joint formed by the lower surface of the talus and the upper surface of the calcaneous enables the foot to be turned outwards or inwards in a rolling motion known as eversion and inversion. Anatomically correct motion of the hind foot is complex as it involves motions that are the combined motions of the motions of the tibio-talar and sub-talar joints.
People with disabling foot conditions, whether congenital, trauma related or idiopathic often benefit from therapies using orthopaedic devices or braces. Such braces typically hold the foot in a prescribed position, allow limited movement of the foot within defined constraints or bias the movement of the foot in a particular way.
Current bracing solutions cannot combine the motions of both the sub-talar and tibio talar joints meaning that in use they cannot support dynamic corrective therapies involving both sub-talar and tibio-talar joints. Current dynamic braces do not enforce anatomically correct motion of both joints.
Current bracing solutions requiring to brace or bias the sub-talar joint achieve this only through the inclusion of a connecting rigid bar between each of the user's feet or through the use of an attachment to the leg which extends well above the knee and is worn with the user's knee in a fixed and substantially bent position. Such braces are inconvenient because the user cannot walk in them and suffer from other inherent disadvantages.
Current general purpose braces to address conditions such as foot drop and many others do not provide dynamic therapy for both tibio-talar and sub-talar joints. Such braces cannot support and reinforce anatomically correct ambulation.